tvm::task_dynamics::VelocityDamper Class Reference

#include <tvm/task_dynamics/VelocityDamper.h>

Inheritance diagram for tvm::task_dynamics::VelocityDamper:

Collaboration diagram for tvm::task_dynamics::VelocityDamper:

Classes
class	AnisotropicConfig
class	Config
class	Impl

Public Member Functions
	VelocityDamper (const Config &config, double big=constant::big_number)
	Velocity damper for first order dynamics. More...
	VelocityDamper (const AnisotropicConfig &config, double big=constant::big_number)
	Velocity damper for first order dynamics. More...
	VelocityDamper (double dt, const Config &config, double big=constant::big_number)
	Velocity damper for second order dynamics. More...
	VelocityDamper (double dt, const AnisotropicConfig &config, double big=constant::big_number)
	Velocity damper for second order dynamics. More...
	~VelocityDamper () override=default
Public Member Functions inherited from tvm::task_dynamics::abstract::TaskDynamics
virtual	~TaskDynamics ()=default
std::unique_ptr< TaskDynamicsImpl >	impl (FunctionPtr f, constraint::Type t, const Eigen::VectorXd &rhs) const
Order	order () const

Protected Member Functions
std::unique_ptr< abstract::TaskDynamicsImpl >	impl_ (FunctionPtr f, constraint::Type t, const Eigen::VectorXd &rhs) const override
Order	order_ () const override
template<typename Derived , typename... Args>
std::unique_ptr< abstract::TaskDynamicsImpl >	impl_ (FunctionPtr f, constraint::Type t, const Eigen::VectorXd &rhs, Args &&... args) const

Detailed Description

A first or second order dynamic task implementing the so-called velocity damper of Faverjon and Tournassoud. For a lower bound tasks e>=0, we have, for e<=di:

• first order: dot{e}_i* = -xsi * (e_i-ds)/(di-ds)
• second order: ddot{e}_i* = -xsi/dt * (e_i-ds)/(di-ds) -dot{e}_i/dt

and for e>di:

• first order: dot{e}* = big
• second order: ddot{e}* = big

For upper bound tasks e <= 0 this is adapted to get the same behavior as -e >= 0.

xsi can be computed automatically (see autoXsi parameter).

Attention

For xsi to be computed automatically in the first order case, the value of dot{e} is used.

To know when to compute xsi in automatic mode, the class keeps data on the last iterations. Consequently if the velocity damper is applied to a function f with variable x, its output value will be the same if x keeps the same value x0 and velocity v0 between two consecutive updates, but the same entries x0 and v0 may give different values for unrelated updates, because of history differences.
This remark only applies when the automatic computation of xsi is required.

Constructor & Destructor Documentation

VelocityDamper() [1/4]

tvm::task_dynamics::VelocityDamper::VelocityDamper	(	const Config &	config,
		double	big = constant::big_number
	)

Velocity damper for first order dynamics.

Parameters

config

configuration of the damper.

See also

VelocityDamperConfig

Parameters

big	value used as infinity.

Attention

When autoXsi is true, the value update will declare a dependency to the Velocity of the error function. It is the user responsibility to ensure the velocity is correctly provided (in particular, this might require the value of the variables first derivatives to be set correctly).

VelocityDamper() [2/4]

tvm::task_dynamics::VelocityDamper::VelocityDamper	(	const AnisotropicConfig &	config,
		double	big = constant::big_number
	)

Velocity damper for first order dynamics.

Parameters

config

configuration of the damper.

See also

VelocityDamperAnisotropicConfig

Parameters

big	value used as infinity.

Attention

Previous remark on autoXsi apply. Furthermore, the dimensions of config must match the function for which this task dynamic will be used.

VelocityDamper() [3/4]

tvm::task_dynamics::VelocityDamper::VelocityDamper	(	double	dt,
		const Config &	config,
		double	big = constant::big_number
	)

Velocity damper for second order dynamics.

Parameters

dt	integration time step to integrate acceleration to velocity (should be the control time step). Must be strictly positive.
config	configuration of the damper.

See also

VelocityDamperConfig

Parameters

big	value used as infinity.

VelocityDamper() [4/4]

tvm::task_dynamics::VelocityDamper::VelocityDamper	(	double	dt,
		const AnisotropicConfig &	config,
		double	big = constant::big_number
	)

Velocity damper for second order dynamics.

Parameters

dt	integration time step to integrate acceleration to velocity (should be the control time step). Must be strictly positive.
config	configuration of the damper.

See also

VelocityDamperAnisotropicConfig

Parameters

big	value used as infinity.

~VelocityDamper()

tvm::task_dynamics::VelocityDamper::~VelocityDamper ( )

overridedefault

Member Function Documentation

impl_() [1/2]

std::unique_ptr<abstract::TaskDynamicsImpl> tvm::task_dynamics::VelocityDamper::impl_ ( FunctionPtr  f, constraint::Type  t, const Eigen::VectorXd &  rhs  ) const

overrideprotectedvirtual

Implements tvm::task_dynamics::abstract::TaskDynamics.

impl_() [2/2]

template<typename Derived , typename... Args>

std::unique_ptr<abstract::TaskDynamicsImpl> tvm::task_dynamics::VelocityDamper::impl_ ( FunctionPtr  f, constraint::Type  t, const Eigen::VectorXd &  rhs, Args &&...  args  ) const

inlineprotected

order_()

Order tvm::task_dynamics::VelocityDamper::order_ ( ) const

overrideprotectedvirtual

Implements tvm::task_dynamics::abstract::TaskDynamics.

---

The documentation for this class was generated from the following file:

• include/tvm/task_dynamics/VelocityDamper.h